Recurrent or Persistent Hematuria

Abstract

Renal biopsies were performed on 47 patients with recurrent macroscopic or persistent microscopic hematuria, unexplained by urinary-tract abnormalities or manifest renal disease. Histologic examination showed a mesangial proliferative glomerulonephritis in 34 patients. Granular deposits of immunoglobulins and complement components were present in the glomerular mesangial area in 15 of 24 biopsies examined by immunofluorescence technics. IgM, β₁C and C1q were deposited in all patients, IgA in 10 patients, and IgG in only two. The intensity of immunofluorescent staining correlated with the glomerular proliferate reaction as judged by light microscopy. Electron-dense granular deposits in the mesangial area were found exclusively in patients with active disease. Thus, the glomerulonephritis in these patients was caused by an IgM and IgA antibody-associated mesangial immune-complex deposition with activation of the classic complement pathway. Follow-up data in 41 patients and repeated renal biopsies in 11 patients indicate a good prognosis. (N Engl J Med 290:1165–1170, 1974)